Current direction and phase
In TRAFOLO, users can modify the winding direction by changing the direction of the current flow through the winding. This adjustment is crucial in inductors, as they oppose sudden current changes by generating a voltage in the opposite direction of the current change. To illustrate this, an existing three-limb inductor template from TRAFOLO is modified to create a two-limb inductor
Modifying Winding Parameters
A two-limb inductor consists of a two-limb core wounded by a Litz wire where distributed air gaps are given in both limbs.
Setting up Windings
In the following example, the Wire Type and Turns per Solid are defined for the winding. Theprimary winding is copied, and a translation along the x-axis is applied to create the secondary winding. The windings are positioned on separate limbs that cross the y-axis.
The Rac/Rdc coefficient is chosen from the Rac computational methods. This coefficient is used to adjust conductor conductivity and calculate AC resistance and losses. The Proximity Factor is only available for the Rac/Rdc coefficient method. The Fill Factor represents a fraction of conductive material in the winding geometry.
Configuring EIMag
Excitation is set to Irms[A] and connect the Coil group connection type in Series to allow current flow through both windings. Ensure both windings are selected as Primary.
Specify positive and negative terminals to indicate the current direction. The terminal type is changed by clicking on that part of the winding where specific colors are given, corresponding to the specific terminal type. Here the orange color represents the positive terminals and the black color represents the negative terminals. Currents can be set to flow in opposite directions by changing the terminal configuration.
Analyzing Results
Total losses and magnetic flux distribution are analyzed inthe Results tab.
Loss Summary
The Summary tab provides the average values of losses and electrical parameters for windings. In the figure below losses for primary winding correspond to both windings.
Winding Components
Under the Component Values tab, it provides voltages and currents for individual winding geometries and winding groups. Complex voltages and currents are given for individual winding geometries. In the figure below DC resistances, AC resistances, RMS Voltage, and RMS current for each coil are shown.
Magnetic Flux Distribution
Magnetic flux is aligned in the same direction, indicating no Flux Cancellation. The current flows in clockwise and anti-clockwise direction in the two coils and a complete flux path is achieved in the core, according to Fleming’s Right Hand Thumb Rule. In the figure below both windings have currents flowing in opposite directions, ensuring correct operation.
